JPH07255008A - Video processing system and video image processing method - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a video processing system having an electronic aperture controller that controls exposure more linearly. A video processing system (10) is provided that includes an image sensor image area (14) operative to transfer an image to an image memory (18) for processing by a video processor (16). The exposure length of the image is controlled by the aperture controller (2) equipped with the signal decoder (30).
4) is controlled. IMGE CLEAR signal is I
It is juxtaposed with the MAGE TRANSFER signal to set the exposure length. The IMAGE CLEAR signal is generated by the aperture counter (36) and the aperture signal decoder (34). The maximum count used by the aperture counter (36) is set using the count length setting circuit (38) which receives the common signal generated by monitoring the video output.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates generally to the field of electronic systems, and more particularly to improved video processing systems.

[0002]

2. Description of the Related Art Electronic aperture controllers have been developed to eliminate or supplement the mechanical aperture that controls the amount of light incident on a solid state electronic image sensor. The electronic aperture controller controls the exposure time by periodic exposure, that is, by removing the charge generated by photon-generated hole electron pairs in the image sensor. This periodic extermination or charge removal process is called image sensor clearing.
Charge is also removed from the image memory when the signal is transferred from the image sensor to the associated image memory. This process is called image transfer. The electronic exposure time is set by the length of time between image clearing and image transfer. The exposure time length can be electronically controlled by changing the relative positions of the image clear operation and the image transfer operation.

The image memory is capacitively coupled with the image sensor. Therefore, while reading information from the image memory, no other operations are performed on the image sensor or the image memory to minimize interference with the reading sequence.
In most television applications, the maximum exposure time for one data field is 16.67 mS. A typical television data field has 262.5 information lines. Because all image clear or image transfer operations must occur during the horizontal blanking or vertical blanking period, this sets a minimum exposure of 63.5 ms for operations during image memory reading. . Aperture control is typically limited to exposure adjustments in 63.5 mS increments only. This incremental change in exposure time causes the percentage change in exposure to be extremely non-linear, making the initial incremental change very small compared to the total field time of 16.67 mS and causing a final incremental change of up to 50%. Occurs.

[0004]

Therefore, there is a need for an electronic aperture controller that controls exposure more linearly. In accordance with the teachings of the present invention, an electronic aperture controller is provided that substantially eliminates or reduces the drawbacks and problems associated with conventional systems.

[0005]

SUMMARY OF THE INVENTION In accordance with one embodiment of the present invention, there is provided a video processing system including an electronic iris controller operable to incrementally change the exposure time associated with the system. The system further comprises an image sensor and image memory for generating and storing image data. The electronic aperture controller is operable to output an image clear signal and an image transfer signal that determines the exposure time of the image.

Referring now to FIG. 1, a video processing system, generally indicated at 10, includes a lens 12 that focuses light onto an image area 14 of an image sensor 15. The image data is periodically transferred from the image area 14 to the image memory 18. The video processor 16 retrieves image data from the image memory 18 and outputs VIDEO OUT.
Output as a PUT signal. VIDEO OUTPUT
The signal is also sent to the first comparator 20 and the second comparator 22. The first comparator 20 is a VIDEO OUTPUT.
The average value of the signal is compared with the first reference voltage V ₁ . Similarly, the second comparator 22 compares the average value of the VIDEO OUTPUT signal with the second reference voltage V ₂ . VIDEO
When the average value of the OUTPUT signal falls below the reference value V _1, it is necessary to increase the exposure of the image. Therefore,
The comparator 20 sends an EXPOSURE signal to the aperture controller circuit 24.
The INCREASE signal is output. Similarly, VIDEO
If the average value of the OUTPUT signal exceeds the reference value V ₂ , then the exposure of the image must be reduced. Therefore, the comparator 22 sends an EXPOSURED signal to the aperture controller 24.
It outputs the ECREASE signal. The aperture controller 24 outputs a signal to the image sensor image area 14 and the image memory 18. Aperture controller 24 operates to control two functions of partial image sensor image area 14 and image memory 18. Image sensor image area 1
4 periodically transfers the image to the image memory 18. Data transfer from the image sensor image area 14 to the image memory 18 causes the charges stored in the image sensor image area 14 to disappear. Image sensor image area 14
The charges therein are generated by photon-generated electron-hole pairs in the semiconductor image sensor image area 14, which are generated by the light focused onto the image sensor image area 14 via the lens 12. Aperture controller 24 also periodically commands image sensor image area 14 to clear the image from image sensor image area 14. This clearing function can also be accomplished by drawing charge from the image sensor image area 14, similar to the method used to transfer charge to the image memory 18. The time between the clearing of the image sensor image area 14 and the transfer of image data from the image sensor image area 14 to the image memory 18 is the electronic exposure time. Therefore,
Aperture controller 24 clears the image sensor image area 14 and controls the time at which a signal instructing the image sensor image area 14 and image memory 18 to transfer image data from the image sensor image area 14 to the image memory 18 occurs. Thereby, the exposure time of the image stored in the image sensor image area 14 can be controlled.

The image sensor image area 14 and the image memory 18 form a charge coupled device that is capacitively coupled to each other. Therefore, the transfer and clear operations controlled by the aperture controller 24 cannot be performed while the video processor 16 is reading image data. When these operations are performed during the reading process,
The image stored in the image sensor may be disturbed.

Typically, video images are each 262.5
It is configured as an interlaced field pair composed of book image data lines. These two fields together form a video frame consisting of 525 scan lines. The image is read from the image memory 18 line by line by the video processor 16. There are typically two types of image sensors and can include an image sensor image area 14 and an image memory 18. One of them is a line addressable image sensor in which each line is transferred to the image memory 18 on an individual basis. The other is a frame transfer image sensor. The frame transfer image sensor transfers the entire image to the image memory at one time. The video processor 16 regardless of whether the image sensor image area 14 and the image memory 18 are a line addressable system or a frame transfer system.
Works the same way. Video processor 16 is VI
It functions to output video image data line by line via the DEO OUTPUT signal.

The video processor 16 has an image memory 18
There is a finite delay after reading out the image data of one line from, and it is called a horizontal blanking period. The horizontal blanking period is the time required for the electron beam to scan horizontally and back across the cathode ray tube (CRT) after drawing a line of image. During the horizontal blanking period, the video processor 16 does not perform any activity on the data stored in the image memory 18. Therefore, the image clear and image transfer functions may occur during the horizontal blanking period.

In addition, there is a long delay called the vertical blanking period at the beginning of each video data feed. The length of the vertical blanking period is typically about 1.27 mS and constitutes the time required for the electron beam to scan back from the bottom right corner to the top left corner of the CRT display. Similar to the horizontal blanking period, the video processor 16 does not perform any operation on the data stored in the image memory 18 during the vertical blanking period. Therefore, the image clear and image transfer functions can occur at any point within the vertical blanking period.

The relative positions of image transfer and image clear control the electronic exposure of the image on the image sensor.
63. The image clear and image transfer functions can be generated.
Only at any time during the horizontal blanking interval that occurs every 5 uS or during the vertical blanking interval that occurs twice during the video Id of the first I-frame of each field and lasts approximately 1.2 mS.

An iris controller 24 constructed in accordance with the teachings of the present invention that implements a floating phase iris controller that allows control of the image sensor 15 approaching linear operation utilizing horizontal and vertical blanking intervals. An example of this is shown in FIG. Referring to FIG. 2, the MASTER CLOCK signal is used to drive the horizontal counter circuit 26.
Horizontal counter circuit 26 is used to address horizontal positions within a line of video image. The horizontal counter circuit 26 uses the MASTERCLOCK until the maximum value is reached.
Driven by the signal, incremented and then reset. When reset, a HORIZONTAL DRIVE signal is generated and output to the vertical counter circuit 28. The horizontal counter value is output to the signal decoder circuit 30.
The vertical counter circuit 28 is incremented each time the horizontal counter circuit 26 reaches its maximum value at the end of the image data line. Therefore, the vertical counter circuit 28 is incremented each time the horizontal blanking period occurs. The value in the vertical counter circuit 28 is also output to the signal decoder 30. The vertical counter circuit 28 counts to a maximum value, which can be, for example, 525, or one count for each line in a complete frame of video data.
When the maximum value is reached, the vertical counter circuit 28 is reset and starts counting from 1. The signal decoder 30 uses the vertical and horizontal counter values to determine when the horizontal blanking and vertical blanking periods occur.

In the embodiment shown in FIG. 2, the IMAGE TR
The ANSFER signal is MASTERCLOCK and HO
It is fixed in phase with the RIZONTAL DRIVE signal. Therefore, in one embodiment of the present invention, whenever the IMAGE TRANSFER signal is transmitted from the signal decoder circuit 30 to the image transfer controller circuit immediately before the vertical blanking period, the signal decoder 30 transfers to the image transfer controller circuit 32. The image TRANSFER ENABLE signal is output.

IMAGE TRANSFER signal is MA
The IMAGE CLE is also transmitted to the image transfer controller circuit 32 because it is fixed in phase with the STER CLOCK and the horizontal counter 26 and the vertical counter 28.
The exposure of the image sensor can be controlled by adjusting the relative position of the AR signal. IMAGE CL
The EAR signal is generated by the diaphragm signal decoder circuit 34 shown in FIG. The aperture signal decoder circuit receives the count from the aperture counter 36. Aperture counter 36 increments with each transition of the accordion clock signal (ACLK). The ACLK signal is called a accordion clock signal because it is a non-linear clock signal with a constant number of transitions with respect to the time required to process one complete frame of video data. However, the transition of the ACLK signal does not occur linearly. Transitions have different durations and can be divided into control zones, which are described in detail here.

The maximum count of the aperture counter is set by the count length setting circuit 38 shown in FIG. The count length setting circuit 38 operates from the signal decoder 30 to the CONTROL.
Receive the ZONE indicator signal. Count length setting circuit 38 also receives the EXPOSURE DECREASE and EXPOSURE INCREASE signals from comparators 20 and 22 described above with reference to FIG.

In operation, the exposure time between the IMAGE CLEAR and IMAGE TRANSFER signals is held constant or adjusted by the aperture counter 36 and aperture signal decoder 34. To keep the exposure time constant, the aperture counter counts the set number of transitions of the ACLK signal. As long as the maximum count length used by the aperture counter 36 does not change, the IMAGE CLEAR signal output from the aperture signal decoder 34 is the IMAGETRANS output from the signal decoder 30.
It is fixed in phase with the FER signal output.

IM until the exposure length reaches the desired time length
AGE CLEAR signal is IMAGE TRANSFEE
The exposure time is adjusted so that it can float in phase with the R signal. The IMAGE CLEAR signal is allowed to float by changing the maximum count length that the iris counter 36 uses to count the transitions of the ACLK signal. The count length is EXPOSURE DECREA
SE signal or EXPOSURE INCREASE
It is changed by the count length setting circuit 38 in response to the signal. The count length is increased by the count length setting circuit 38 to decrease the exposure length and is decreased to increase the exposure length.

Referring to FIG. 3, there is shown a side-by-side timing diagram of some signals used in the operation of the system of the present invention. The first line in Figure 3 is FIELD INDIC
This is the ATOR signal. A low value on the field indicator indicates that the first field of the frame is being processed and a high value on the FIELD INDICATOR signal indicates that the second field of the frame is being processed. The second line in FIG. 2 is the VERTICAL BLAN
The KING INDICATOR signal is shown. The vertical blanking interval shown occurs at the beginning of each field and lasts approximately 1.27 mS. The next line in Figure 3 is IMAGE
The TRANSFER signal is shown. The image transfer signal is a signal having a very short duration that occurs immediately before the vertical blanking period ends. As mentioned above, IMAGE TRANS
An image can be transferred from the image sensor image area 14 to the image memory 18 by the FER signal. This transfer requires approximately 10 umS.

The next line in FIG. 3 is HORIZONTAL.
The transition of the DRIVE signal is shown. HORIZONTAL
Each vertical line in the DRIVE signal represents a transition that coincides with the horizontal blanking period. For clarity, the actual duration of the horizontal drive transition is not shown. The actual transition occurs every 63.5 uS and there are 525 transitions between the beginning of field 1 and the end of field 2. Furthermore, during the vertical blanking period, about 21 actual HORI
There is a transition of the ZONTAL DRIVE signal. For the sake of clarity and to teach the advantages of the present invention, HORIZON
The transition of the TAL DRIVE signal is shown to be much larger H
ORIZONTAL DRIVE signal followed by AC
The relationship of LK signals is understood.

As described above with reference to FIG. 2, the aperture counter 36 receives the ACLK signal from the signal decoder 30 and uses it to trigger its counting operation. Aperture signal decoder 34 produces an IMAGE CLEAR signal in response to the value in aperture counter 36. Therefore, the aperture signal decoder 34 and the IMAGE CLEA
The R signal is effectively clocked off from the ACLK signal.
As shown in FIG. 3, the IMAGE CLEAR signal is AC
Corresponds to the transition of the LK signal. When the maximum count value of the aperture counter 36 is changed by the count length setting circuit 38, the IMAGECLEAR signal floats to the next transition of the ACLK signal as shown by the broken line at reference numeral 42 in FIG. 3 to enable the exposure time of the system. Reduce. The position of the IMAGE CLEAR signal for maximum exposure is shown in FIG.
It is indicated by 0.

IMAGE CLEAR signal is HORIZ
Image clear is HORIZONTAL D when clocked directly by the ONTAL DRIVE signal.
Float from one transition of the RIVE signal to the next in uniform increments. IMAGE CLEAR signal phase is IMA
Although this exposure adjustment method causes the exposure time to change uniformly because it floats with respect to the phase of the GE TRANSFER signal, the percentage change of each incremental change changes extremely nonlinearly. For example, IMAGECLEA which gives the longest exposure period
The initial increment from the R signal value to the next longer period is approximately 0.
That is a 4% change. In contrast, the final incremental change from the next shortest exposure time to the shortest exposure time consists of 50% exposure change.

In order for the feedback process described in FIG. 1 to operate more efficiently, the percentage exposure change should be as close to a linear relationship as possible. Two methods are used in the system of the present invention to make the exposure variation more linear.

The first method of adjusting the linearity of the exposure change produces a non-linear clock signal ACLK. As shown in FIG. 3, the ACLK signal consists of a fixed number of transitions for the length of time required for a complete frame of video data. However, the transitions are unevenly spaced to allow long transitions at the beginning of the field and extremely short transitions during the vertical blanking interval. As mentioned above, the image clearing process must occur during the horizontal blanking period or the vertical blanking period. Thus, for example, each transition of the ACLK signal in region 44 of FIG. 3 occurs during the horizontal blanking interval. Therefore, there are 6 transitions in region 44.
It cannot occur more frequently than 3.5 uS. However, this constraint does not apply during the vertical blanking period shown in region 46 of FIG. Therefore, the transition of the ACLK signal in the region 46 can be at any interval.

Region 44 may also be subdivided into regions 48 and 50 as shown in FIG. In one embodiment of the present invention, the region 48 is generated every two horizontal blanking periods.
There is one transition of the ACLK signal within. Within region 50, a transition of the ACLK signal occurs each time a horizontal blanking period occurs. As the ACLK signal progresses, the incremental floating of the IMAGE CLEAR signal from one transition to another transitions greatly step in regions such as regions 48 and 50 of the time base and becomes very thin in other regions of the time base such as region 46. . This variability in transition length improves the linearity of the percentage change in exposure time. Non-linear clock signal AC
The change in exposure time from position 40 to position 42 due to actuation of LK, for example, will exhibit approximately the same percentage exposure change as the change from position 52 to position 54 in FIG.

Also shown in FIG. 3 are the IRIS STOP UP and IRIS STOP DOWN signals, which are generated by the signal decoder 30 to allow the IMAGE CLEAR signal to float past a predetermined limit as the exposure time changes. To prevent. IMAGE CLEA
If the R signal continues to float, it will immediately pass from the shortest exposure setting to the longest exposure setting. This is IRIS ST
Prevented by the OP UP and IRIS STOP DOWN signals.

FIG. 3 shows three typical control range signals, namely, CONTROL ZONE 1 signal and CONTROL.
L ZONE 2 signal and CONTROL ZON
The E3 signal is also shown. CONTROL ZONE
The signal is used in the system of the present invention to achieve the second method of improving the linearity of the exposure variation of the system. C
Where the ONTROL ZONE signal is in the time base
The count length setting circuit 38 indicates whether the MAGE CLEAR signal is present. For example, CONTROLZONE
1 signal is active in the region 48, CONT
The ROL ZONE 2 signal is active in the area 50 and the CONTROL ZONE 3 signal is active in the area 46 corresponding to the vertical blanking period.
The CONTROL ZONE signal is used to provide a change in maximum count of the aperture counter 36 greater than one. For example, during the time-based initial phase in region 48, the aperture counter 36 may increase the maximum count to 2 instead of 1.
By changing the above, the IMAGE CLEAR signal can be changed to 2
It can be transitioned more than once. IMAG by changing the maximum count of the aperture counter 36
IMAGE CLE for E TRANSFER signal
It is also possible to speed up the transition of the AR signal. CONTR
The OL ZONE signal is used to generate a more linear percentage exposure change response by dividing the time base into regions and combining the non-linear ACLK clock signal with the use of a selective maximum count for the aperture counter. CONTROL ZONE signal and A included in the embodiment
The transitions of the CLK signal are solely for the purpose of teaching the advantages of the invention and the invention is not limited to this or any representative embodiment. CONTROL ZONE
Any number of signal and ACLK signal transitions can be combined to produce any desired exposure response.

While the present invention has been described in detail, various changes, substitutions and modifications can be made to the teachings disclosed herein within the spirit and scope of the invention, the scope of which is defined by the following claims. It should be understood that it is only specified. The following items are further disclosed with respect to the above description. (1). A video processing system, the system comprising:
An image sensor that has an image area that operates to receive light and form image data that represents an image, and that operates to clear the image data from the image sensor in response to an image clear signal, and an image sensor image area. An image memory that receives image data from the connected image sensor image area and stores the image data in response to the exposure time associated with the image defined as the time between the image transfer signal, the image clear signal and the image transfer signal, and the image An electronic aperture control circuit connected to a sensor image area and an image memory and operable to generate an image clear signal and an image transfer signal, said control circuit being operable to change the exposure time in successive increments, At least some of the incremental increments will have a duration that decreases with decreasing exposure time and It said electronic throttle control circuit having a variable length with a duration of increasing with increasing light time,
A video processing system comprising:

(2). The video processing system of claim 1, wherein the electronic aperture controller circuit generates an accordion clock signal having a fixed number of transitions for a given time period and a variable time period for at least some transitions. A signal decoder circuit that operates in the manner described above, and operates to increment the aperture count value in response to the accordion clock signal by being connected to the signal decoder circuit via the accordion clock signal, and further stops when the predetermined aperture count value is reached. An aperture counter circuit that operates to reset the count value, and an aperture signal decoder that is connected to the aperture counter circuit and that operates to generate and output an image clear signal in response to the aperture counter circuit reaching a predetermined count value. A given aperture in response to the circuit and the exposure signal indicating the need to change the exposure time. Video processing system comprising a count length set circuit operable to alter the count value.

(3). The video processing system of claim 2, wherein the signal decoupling circuit is operative to generate the image transfer signal at predetermined intervals having a substantially constant duration.

(4). A video processing system according to claim 2, wherein the signal decoder circuit is connected to the count length setting circuit via at least one control range signal, and the control range signal is related to the required change of the exposure time, A video processing system in which the length setting circuit operates to change a predetermined aperture count value by a variable value in response to a control range signal.

(5). The video processing system according to the second item, wherein the signal decoder circuit is connected to a count length setting circuit via a control range signal, and the control range signal is related to a required change of the exposure time. Sets a predetermined aperture count value to 1 in response to a certain value of the control range signal
A video processing system that operates to change by a larger change value.

(6). The video processing system of claim 2, wherein the exposure signal comprises an exposure enhancement signal and an exposure reduction signal, the system further connected to the image memory and operable to retrieve the image data from the image memory and the image memory. A video processing circuit operative to output to the display a video signal representative of the video signal and a first comparison between the video signal and the first predetermined comparator signal. A first comparator that selectively outputs an exposure enhancement signal in response to the first comparison and a video signal and a second predetermined comparator signal connected to the video signal and the second predetermined comparator signal. And a second comparator that selectively outputs an exposure reduction signal in response to the second comparison.

(7). The video processing system of claim 2, wherein the signal decoder circuit is further operative to generate and output an iris stop up signal and an iris stop down signal that limit the modification of the exposure time.

(8). A video processing system, the system comprising an image area operative to receive light from a subject to form an image and operative to clear an image from an image sensor in response to an image clear signal. Responsive to the image sensor and the image-related exposure time defined as the time between the image transfer signal, the image clear signal and the image transfer signal, which is connected to the image sensor image area and receives image data representing the image from the image sensor image area And an image memory that operates to store image data, and that operates to generate and transmit an image clear signal and an image transfer signal that are connected to the image sensor image area and the image memory, and the exposure time in increments. Behaves differently, with at least some of the incremental increments tapering off as the exposure time decreases. And an electronic iris controller circuit having a variable length having a gradually increasing duration with increasing exposure time, the electronic iris controller circuit having a fixed number of transitions for a given period. Operative to generate an accordion clock signal having a variable period for at least some transitions, and operative to generate an image transfer signal at predetermined intervals having a substantially constant duration. Connected to the signal decoder circuit and the signal decoder circuit via the accordion clock signal, it operates to increment the iris count value in response to each transition of the accordion clock signal, and when the maximum iris count value is reached, the iris count value is reached. The aperture counter circuit that operates to reset the Aperture signal decoder circuit that operates to generate and output an image clear signal in response to reaching a certain count value, and the maximum aperture count is changed in response to an exposure signal indicating the need to change the exposure time A video processing system, comprising: a count length setting circuit operable to operate.

(9). A video processing system according to claim 8, wherein the signal decoder circuit is connected to the count length setting circuit via at least one control range signal, each control range signal being associated with a required change in exposure time, A video processing system wherein the count length setting circuit operates to change a predetermined aperture count value by a change value in response to a control range signal.

(10). In the video processing system according to item 8, the signal decoder circuit is connected to a count length setting circuit via a control range signal, and the control range signal is related to a required change in exposure time, A circuit is operative to change a predetermined aperture count value by a change value greater than one in response to a control range signal.

(11). The video processing system of claim 8, wherein the exposure signal comprises an exposure increase signal and an exposure reduction signal, the system further connected to the image memory and operable to retrieve the image data from the image memory and the image signal. A video processing circuit operative to output a video signal representing the video signal to the display;
A first comparator connected to the predetermined comparator signal for comparing the video signal with the comparator signal and selectively outputting the exposure enhancement signal in response to the comparison; and the video signal and the second predetermined comparator signal. A second comparator coupled to the comparator for comparing the video signal with the comparator signal and selectively outputting the exposure reduction signal in response to the comparison.

(12). The video processing system of claim 8, wherein the signal coder circuit is further operative to generate an iris stop up signal and an iris stop down signal operative to limit the change in exposure time.
Video processing system.

(13). A video image processing method,
The method includes forming an image using an image sensor having an image area by receiving light from a subject, clearing the image from the image sensor in response to an image clear signal, and collecting the image from the image sensor. Image data is stored in response to an exposure time associated with the image, which is defined as the time between the image transfer signal, the image clear signal and the image transfer signal in the image memory that receives the image data representing and is connected to the image sensor image area. A step of generating and transmitting an image clear signal and an image transfer signal using the electronic aperture control circuit connected to the image sensor and the image memory, and sequentially incrementing using the electronic aperture control circuit. A step of varying the exposure time, wherein at least some of the incremental increments are associated with a decrease in the exposure time. Wherein comprising a step, a video image processing method having a variable length with a duration of increasing as the duration and the exposure time for increasing the decreasing Te.

(14). The method according to paragraph 13,
Further, in the signal decoder circuit, generating an accordion clock signal having a fixed number of transitions for a given time period, but having a variable time period for at least some transitions, and via the accordion clock signal. The aperture counter circuit connected to the signal decoder circuit increments the aperture count value in response to the accordion clock signal, the step of resetting the aperture count value when the maximum aperture count value is reached, and the aperture counter Generating and outputting an image clear signal in response to the circuit reaching the maximum count value, and changing the maximum aperture count value in response to the exposure signal indicating the need to change the exposure time. Video image processing method including.

(15). The method according to paragraph 14,
A method for processing video images, further comprising the step of generating image transfer signals at predetermined intervals having a substantially constant duration.

(16). The method according to paragraph 14,
Further, it comprises a step of changing the maximum aperture count value by a change value in response to the control range signal, and the signal decoder circuit is connected to the count length setting circuit via at least one control range signal, and each control range signal is exposed. A video image processing method that is related to the required change in time.

(17). The method according to paragraph 14,
Further, in response to the control range signal, the maximum aperture count value is changed by a change value larger than 1, and the signal decoder circuit is connected to the count length setting circuit via the control range signal, and the control range signal is exposed. Video image processing methods related to the required change in time.

(18). The method according to paragraph 14,
The exposure signal consists of an exposure increase signal and an exposure decrease signal,
The method further comprises retrieving the image data from the image memory and outputting a video signal representative of the image to a display, the video signal and the video signal at a first comparator to which the first predetermined comparator signal is connected. Making a first predetermined comparison with a first predetermined comparator signal;
Selectively outputting an exposure enhancement signal in response to the comparison of the video signal and the second predetermined comparator signal to the video signal and the second predetermined comparator signal. And a step of selectively outputting an exposure enhancement signal in response to the second comparison.

(19). The method according to paragraph 13,
A method of processing a video image, further comprising the steps of generating an aperture stop up signal and an aperture stop down signal operative to limit a change in exposure time.

(20). Video processing system (10)
Which is provided with an image sensor image area (14) operative to transfer images to the image memory (18) for processing by the video processor (16). The exposure length of the image is controlled by an aperture controller (24) equipped with a signal decoder (30). IMGE CLE
The AR signal is juxtaposed with the IMAGE TRANSFER signal to set the exposure length. The IMAGE CLEAR signal is used as an aperture counter (36) and an aperture signal decoder (34).
Generated by. The maximum count used by the aperture counter (36) is set using the count length setting circuit (38) which receives the common signal generated by monitoring the video output.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a video processing system configured in accordance with the teachings of the present invention.

FIG. 2 is a schematic block diagram of an aperture controller circuit constructed in accordance with the teachings of the present invention.

FIG. 3 is a timing diagram showing some signals used in the aperture controller and video processing system of the present invention.

[Explanation of symbols]

 10 Video Processing System 12 Lens 14 Image Sensor Image Area 15 Image Sensor 16 Video Processor 18 Image Memory 20 Comparator 22 Comparator 24 Aperture Controller 26 Horizontal Counter 28 Vertical Counter 30 Signal Decoder 32 Image Transfer Controller 34 Aperture Signal Decoder 36 Aperture Counter 38 Count length setting circuit

Claims (2)

[Claims] 1. A video processing system, the system having an image area operative to receive light to form image data representative of an image, the image data from an image sensor in response to an image clear signal. Associated with an image sensor that operates to clear the image sensor and receives image data from the image sensor image area that is connected to the image sensor image area and defined as the image transfer signal, the time between the image clear signal and the image transfer signal An image memory that stores image data in response to an exposure time, and an electronic aperture control circuit that is connected to the image sensor image area and the image memory and that operates to generate and transmit an image clear signal and an image transfer signal, The control circuit is operable to change the exposure time in successive increments, At least some of said electronic iris control circuits having a variable length with a duration that gradually decreases as the exposure time decreases and a duration that gradually increases as the exposure time increases. 2. A method of processing a video image, the method comprising: forming an image using an image sensor having an image area by receiving light from a subject; and the image sensor in response to an image clear signal. Clearing the image from the image sensor and the image transfer signal in the image memory that receives the image data representing the image from the image sensor and is connected to the image sensor image area Storing image data in response to an exposure time associated with, and generating and transmitting an image clear signal and an image transfer signal using an electronic aperture control circuit connected to the image sensor and the image memory, A step of changing the exposure time by sequentially incrementing the exposure time using an electronic aperture control circuit. Te, sequential increment at least some including a step having a length having a duration gradually increases with increasing duration and exposure time gradually decreases with decreasing exposure time, a video image processing method.